The brain is the highest nucleus organ of the nervous system, placed in the head. The brain consists of cerebrum, cerebellum, midbrain (mesencephalon), pons, and medulla, and generates brainwaves. The brainwave, as also known as electroencephalography (EEG), is a current of electricity generated in the course of transmission of signals between the brain nerves in the nervous system. The brainwave differs depending on the information the brain processes, and is the most important indicator for measuring brain activity.
Applying electrical stimulation to brain may help relieve or alleviate neurological symptoms such as hand tremor. There are invasive and noninvasive methods for electrical stimulation of the brain. The invasive method is to insert an electrode to the brain and to transmit the electrical signal to the electrode. On the other hand, the noninvasive method is to attach the electrode to scalp and to transmit the electrical signal to the electrode.
The noninvasive electrical stimulation has an advantage of lower cost and risk than the invasive method. Accordingly, research and development about the noninvasive electrical stimulation of the brain has been carried out.